U.S. patent number 8,716,943 [Application Number 13/027,788] was granted by the patent office on 2014-05-06 for light-emitting device and lighting apparatus provided with the same.
This patent grant is currently assigned to Toshiba Lighting and Technology Corporation. The grantee listed for this patent is Seiko Kawashima, Tsuyoshi Oyaizu, Akiko Saito, Haruki Takei. Invention is credited to Seiko Kawashima, Tsuyoshi Oyaizu, Akiko Saito, Haruki Takei.
United States Patent |
8,716,943 |
Oyaizu , et al. |
May 6, 2014 |
Light-emitting device and lighting apparatus provided with the
same
Abstract
According to one embodiment, a light-emitting device includes a
substrate including an insulating surface, a plurality of
light-emitting elements mounted on the surface of the substrate and
electrically connected to each other, a positive power feeding
conductor and a negative power feeding conductor mounted on the
surface of the substrate to feed power to the light-emitting
elements, lead-out terminals leading from the power feeding
conductors, to the outside of an mounting area of the
light-emitting elements, and an anti-noise part connected to the
lead-out terminals and arranged outside the mounting area.
Inventors: |
Oyaizu; Tsuyoshi (Yokosuka,
JP), Kawashima; Seiko (Yokosuka, JP),
Takei; Haruki (Yokosuka, JP), Saito; Akiko
(Yokosuka, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Oyaizu; Tsuyoshi
Kawashima; Seiko
Takei; Haruki
Saito; Akiko |
Yokosuka
Yokosuka
Yokosuka
Yokosuka |
N/A
N/A
N/A
N/A |
JP
JP
JP
JP |
|
|
Assignee: |
Toshiba Lighting and Technology
Corporation (Kanagawa, JP)
|
Family
ID: |
44148707 |
Appl.
No.: |
13/027,788 |
Filed: |
February 15, 2011 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20110199021 A1 |
Aug 18, 2011 |
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Foreign Application Priority Data
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Feb 16, 2010 [JP] |
|
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2010-030806 |
Jun 28, 2010 [JP] |
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2010-146730 |
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Current U.S.
Class: |
315/185R;
362/249.01; 315/294 |
Current CPC
Class: |
H05B
45/50 (20200101); H05B 45/00 (20200101); H01L
2924/181 (20130101); H05B 45/38 (20200101); H05B
45/345 (20200101); H01L 2224/48091 (20130101); H01L
2224/45144 (20130101); H01L 2224/48137 (20130101); H05B
45/355 (20200101); H01L 2224/73265 (20130101); H05B
45/34 (20200101); H01L 2224/48091 (20130101); H01L
2924/00014 (20130101); H01L 2224/45144 (20130101); H01L
2924/00 (20130101); H01L 2924/181 (20130101); H01L
2924/00012 (20130101) |
Current International
Class: |
H05B
37/02 (20060101); F21S 4/00 (20060101) |
Field of
Search: |
;315/200R,209R,224,225,291,307,185R,294 ;362/249.01,235 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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101589266 |
|
Nov 2009 |
|
CN |
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0191261 |
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Aug 1986 |
|
EP |
|
2180765 |
|
Apr 2010 |
|
EP |
|
2009-54989 |
|
Mar 2009 |
|
JP |
|
2009-071227 |
|
Apr 2009 |
|
JP |
|
2009-164567 |
|
Jul 2009 |
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JP |
|
2009-290244 |
|
Dec 2009 |
|
JP |
|
WO 01/01385 |
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Jan 2001 |
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WO |
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WO 2004/068909 |
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Aug 2004 |
|
WO |
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WO 2009/104645 |
|
Aug 2009 |
|
WO |
|
Other References
English Language Abstract of JP 2009-54989 published Mar. 12, 2009.
cited by applicant .
English Language Translation of JP 2009-54989 published Mar. 12,
2009. cited by applicant .
English Language Abstract of JP 2009-290244 published Dec. 10,
2009. cited by applicant .
English Language Translation of JP 2009-290244 published Dec. 10,
2009. cited by applicant .
Chinese Office Action issued in CN 201110038806.6 on Feb. 5, 2013.
cited by applicant .
English Language Abstract of Chinese Office Action issued in CN
201110038806.6 on Feb. 5, 2013. cited by applicant .
English Language Abstract of WO 2009/104645 published Aug. 27,
2009. cited by applicant .
English Language Abstract of JP 2009-071227 published Apr. 2, 2009.
cited by applicant .
English Language Translation of JP 2009-071227 published Apr. 2,
2009. cited by applicant .
Chinese Office Action issued in CN 201110038806.6 on Oct. 15, 2013.
cited by applicant .
English Language Translation of Chinese Office Action issued in CN
201110038806.6 on Oct. 15, 2013. cited by applicant .
English Language Abstract of CN 101589266 published Nov. 25, 2009.
cited by applicant .
Japanese Office Action issued in JP 2010-030806 issued Jul. 2,
2013. cited by applicant .
English Language Translation of Japanese Office Action issued in JP
2010-030806 issued Jul. 2, 2013. cited by applicant .
English Language Abstract of JP 2009-164567 published Jul. 23,
2009. cited by applicant .
English Language Translation of JP 2009-164567 published Jul. 23,
2009. cited by applicant .
European Search Report issued in European Application No.
11154499.5 dated Nov. 22, 2013. cited by applicant .
English Language Abstract of EP 0191261 published Aug. 20, 1986.
cited by applicant.
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Primary Examiner: Vu; Jimmy
Attorney, Agent or Firm: DLA Piper LLP (US)
Claims
What is claimed is:
1. A light-emitting device comprising: a substrate including an
insulating surface: a plurality of light-emitting elements mounted
on the surface of the surface of the substrate and electrically
connected to each other; a positive power feeding conductor and a
negative power feeding conductor disposed on the surface of the
substrate to feed power to the light-emitting elements; lead-out
terminals leading from the power feeding conductors, to the outside
of an mounting area of the light-emitting elements; and an
anti-noise part connected to the lead-out terminals and arranged
outside the mounting area, wherein the anti-noise part includes a
plurality of the same elements, the lead-out terminals include a
pair of lead-out conductors continued respectively from each of the
power feeding conductors, and at least one connection conductor is
placed between edges of the lead-out conductors with a
predetermined distance.
2. The light-emitting device according to claim 1, wherein the same
elements are connected between the lead-out conductor and the
connection conductor, or between either of the connection conductor
and the other connection conductor.
3. The light-emitting device according to claim 1, further
comprising a reflection layer formed on the mounting area of the
substrate, wherein the light-emitting elements are mounted on the
reflection layer, and the anti-noise part is arranged outside the
reflection layer.
4. The light-emitting device according to claim 1, further
comprising a frame member on the substrate, surrounding the
mounting area; and a sealing member filled on the light-emitting
elements, inside the frame member, wherein the anti-noise part is
arranged outside the frame member.
5. The light-emitting device according to claim 1, further
comprising a power feeding connector mounted on the substrate and
connected to the positive power feeding conductor and the negative
power feeding conductor; wherein the power feeding connector is
higher than the anti-noise part and placed outside the anti-noise
part with respect to the mounting area.
6. A lighting apparatus comprising: an apparatus main body: a
light-emitting device arranged in the apparatus main body, the
light-emitting device including: a substrate including an
insulating surface; a plurality of light-emitting elements mounted
on the surface of the substrate and electronically connected to
each other; a positive power feeding conductor and a negative power
feeding conductor disposed on the surface of the substrate to teed
power to the light-emitting elements; lead-out terminals leading
from the power feeding conductors, to the outside of a mounting
area of the light-emitting elements; and an anti-noise part
connected to the lead-out terminals and arranged outside the
mounting area; and a lighting control device configured to supply
power to the light-emitting device, wherein the anti-noise part
includes a plurality of the same elements, the lead-out terminals
include a pair of lead-out conductors continued respectively from
each of the power feeding conductors, and at least one connection
conductor placed between edges of the lead-out conductors with a
predetermined distance.
7. The lighting apparatus according to claim 6, wherein the same
elements are connected between the lead-out conductor and the
connection conductor, or between either of the connection conductor
and the other connection conductor.
8. The lighting apparatus according to claim 6, further comprising
a reflection layer formed on the mounting area of the substrate,
wherein the light-emitting elements are mounted on the reflection
layer, and the anti-noise part is arranged outside the reflection
layer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority
from Japanese Patent Applications No. 2010-030806, filed Feb. 16,
2010; and No. 2010-146730, filed Jun. 28, 2010; the entire contents
of both of which are incorporated herein by reference.
FIELD
Embodiments described herein relate generally to a light-emitting
device using a light-emitting element such as an LED, and a
lighting apparatus provided with the light-emitting device.
BACKGROUND
Recently, a light-emitting diode (LED) has been used as a light
source of a lighting apparatus. In this light source, a number of
LED bare chips are mounted on a substrate, and each LED chip is
electrically connected to a wiring pattern by bonding wires. A
plurality of such substrates is housed in a main body made of metal
such as aluminum (Jpn. Pat. Appln. KOKAI Publication No.
2009-54989).
In such a lighting apparatus, power is usually supplied from a
lighting control device connected to commercial power source, and
lighting of the LED chip is controlled. The metallic main body is
maintained at a ground potential.
However, in the above lighting apparatus, though a power switch
(one-position) of the lighting control device is being turned off,
an LED chip is accidentally lit dimly. This phenomenon is caused by
a noise superimposed on a power line. Stray capacitance is
generated between a conductor such as the wiring pattern connected
to the LED chips and the metallic main body close to the conductor,
and a minute current flows in the LED chip as a leakage
current.
Further, when the power switch is turned on, a rush current may
flow into LED chips as a noise, and break the LED chips. As well
known, an LED is weak to electrostatic breakdown, and is easily
broken when subjected to a high voltage caused by a noise such as
static electricity. For example, a worker may touch a wiring
pattern while assembling a lighting apparatus. In such a case, if
the worker's hand is electrostatically charged, an overcurrent is
applied to an LED, and damages or breaks the LED. In addition, jigs
and tools electrostatically charged during the assembling work
discharges electricity, an overcurrent is applied to an LED, and
damages or breaks the LED, decreasing the reliability.
To solve the above problems, or to prevent accidental lighting, a
capacitor is inserted as a bypass element in parallel to an LED
chip. To prevent a damage or breakage of an LED by static
electricity, a capacitor or a constant-voltage diode is inserted as
a protective element.
These capacitor and constant-voltage diode as anti-noise parts may
be mounted on a circuit board of a power supply circuit, or mounted
together with an LED on the same substrate.
However, when the capacitor and constant-voltage diode as
anti-noise parts are mounted on a circuit board of a power supply
circuit, a wiring pattern and land are additionally provided on the
circuit board, and the components must be connected to these
pattern and land, resulting in a complex structure. Further, when
such components are mounted together with LEDs on the same
substrate on which the LEDs are mounted as a light-emitting
element, the anti-noise parts obstruct the light emitted from the
LEDs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front plan view of a light-emitting device according to
a first embodiment;
FIG. 2 is a plan view of the light-emitting device before
anti-noise parts and connectors are mounted;
FIG. 3 is a sectional view of the light-emitting device along line
in FIG. 1;
FIG. 4 is a circuit configuration of a lighting apparatus according
to a first embodiment;
FIG. 5 is a schematic connection diagram of the lighting
apparatus;
FIG. 6 is a sectional view of a lighting apparatus according to a
second embodiment;
FIG. 7 is a front plan view of a light-emitting device according to
a third embodiment;
FIG. 8 is a plan view of the light-emitting device before
anti-noise parts and connectors are mounted;
FIG. 9 shows a circuit configuration of a lighting apparatus
according to a fourth embodiment;
FIG. 10 is a perspective view of a street light according to a
fifth embodiment;
FIG. 11 is a perspective view of the street light;
FIG. 12 is a front plan view of a light-emitting device of the
street light according to the fifth embodiment;
FIG. 13 is a plan view of the light-emitting device before
anti-noise parts and connectors are mounted; and
FIG. 14 is a sectional view of the light-emitting device.
DETAILED DESCRIPTION
In general, according to one embodiment, a light-emitting device
comprises a substrate including an insulating surface; a plurality
of light-emitting elements mounted on the surface of the substrate
and electrically connected to each other; a positive power feeding
conductor and a negative power feeding conductor disposed on the
surface of the substrate to feed power to the light-emitting
elements; lead-out, terminals leading from the power feeding
conductors, to the outside of an mounting area of the
light-emitting elements; and an anti-noise part connected to the
lead-out terminals and arranged outside the mounting area.
A substrate may be made of ceramic material or synthetic resin
material such as glass epoxy resin, or may be formed of a metallic
base board with an insulating layer formed on one side of a base
plate such as aluminum with high thermal conductivity and heat
radiation. A light-emitting element is a solid light-emitting
element such as an LED. The number of mounted light-emitting
elements is not particularly limited.
Positive and negative power feeding conductors, and a lead-out
terminal are made of conductive material such as copper foil. A
conductive part has a three layered structure. A first layer may be
formed by etching copper. On the copper layer, nickel (Ni) may be
plated as a second layer. Silver (Ag) may be plated as a third
layer. According to the embodiment, an anti-noise part is connected
by using the positive and negative power feeding conductors.
An anti-noise part is a part for preventing accidental lighting,
damage or breakage of a light-emitting element due to, e.g., noises
superimposed on a power line or caused by static electricity and
the like. Such a part is connected parallel to a connection circuit
of a light-emitting element, and functions as a bypass element or a
protective element. A capacitor and a constant-voltage diode are
used as an anti-noise part, but the anti-noise part is not limited
to these components.
According to the embodiment, in the light-emitting device, the
anti-noise part comprises a plurality of the same elements, the
lead-out terminal comprises a lead-out conductor continued from the
positive and negative power feeding conductors, and at least one
connection conductor is provided with predetermined distance
between the edges of the lead-out conductor. The same elements are
connected between the lead-out conductor and connection conductor,
or between one connection conductor and the other connection
conductor.
The same elements mean a plurality of capacitors as a protective
element connected and mounted in series. This structure can set the
distance between conductors longer.
The lighting apparatus according to the embodiment comprises an
apparatus main body, a lighting device arranged in the main body,
and a lighting control device configured to supply power to the
light-emitting device. The lighting apparatus includes a light
source and a lighting fixture used indoors and outdoors, and a
display unit.
According to the embodiment, it is possible to provide a
light-emitting device and lighting apparatus, which are configured
to prevent defects caused by noises, and simply constructed so that
an anti-noise part does not obstruct the light emitted from each
light-emitting element. It is also possible to prevent
deterioration of insulation caused by a migration phenomenon.
Hereinafter, a lighting apparatus according to a first embodiment
will be explained with reference to FIGS. 1 to 5. FIGS. 1, 2, and 3
show a light-emitting device of the lighting apparatus. FIG. 4
shows the lighting apparatus. The same parts in the drawings are
given the same reference numbers, and an explanation thereof is
omitted.
As shown in FIGS. 1 to 3, a light-emitting device 1 of a lighting
apparatus comprises a substantially rectangular substrate 2, and a
number of light-emitting elements 3 mounted on the substrate 2, and
an anti-noise part 4. On the front surface of the substrate 2, for
example, a rectangular reflection layer 5 is formed, and the
light-emitting elements 3 are mounted on the reflection layer 5. In
the circumference of the reflection layer 5 on the substrate 2, a
positive power feeding conductor 6, a negative power feeding
conductor 7, a pair of lead-out terminals 6, a pair of power
feeding terminals 9, a frame member 10, and a sealing member 11
covering the light-emitting elements 3 are provided.
The substrate 2 is made of ceramics such as white aluminum oxide or
aluminum nitride for forming an insulating layer. The reflection
layer 5 is formed at the center of the front surface of the
substrate 2. On the reflection layer 5, 100 or more light-emitting
elements 3 are bonded with a silicon resin adhesive.
The substrate 2 may be made of a metallic substrate with an
insulating layer formed on one side of a base plate such as
aluminum with high thermal conductivity and heat radiation, to
increase the heat radiation of each light-emitting element 3. The
substrate 2 may be made of synthetic resin material with insulation
property such as glass epoxy resin.
On the front surface of the substrate 2, the reflection layer 5,
positive power feeding conductor 6, negative power feeding
conductor 7, lead-out terminals 8, and power feeding terminals 9
are formed. The reflection layer 5 is shaped substantially
rectangular. The positive power feeding conductor 6 and negative
power feeding conductor 7 are formed parallel to the opposing two
sides of the reflection layer 5, with a distance (insulation
distance) to the reflection layer 5. A pair of lead-out terminals 8
continuously extends in the substantially orthogonal direction from
one ends of the positive power feeding conductor 6 and negative
power feeding conductor 7. The ends of the lead-out terminals 8 are
opposed with a predetermined distance (insulating distance) L.
From the other ends of the positive power feeding conductor 6 and
negative power feeding conductor 7, power feeding terminals extend
in the substantially orthogonal direction, and the extended ends
are opposed with a predetermined distance.
As shown in FIG. 3, the reflection layer 5 has a three-layered
structure, for example. On the front surface of the substrate 2, a
copper pattern layer is formed by etching as a first layer 5a. A
second layer 5b is a plated layer formed by plating nickel (Ni) on
the copper pattern layer. A third layer 5c is a plated layer formed
by plating silver (Ag) on the second nickel-plated layer. The third
layer 5c of the reflection layer 5, that is, the silver-plated
front layer has a high total reflectivity of 90%.
The positive power feeding conductor 6, negative power feeding
conductor 7, lead-out terminals 8, and power feeding terminals 9
have two-layered-structure. A first layer a is formed by a copper
pattern, and a second layer b is formed by a resist layer formed on
the copper pattern. Similar to the reflection layer 5, the positive
power feeding conductor 6, negative power feeding conductor 7,
lead-out terminal 8, and power feeding terminal 9 may be
constructed in a three-layered structure of copper, nickel and
silver. The light-emitting element 3 can be directly bonded to the
substrate 2, without forming a reflection layer 5.
A plurality of light-emitting elements 3 uses LED bare chips. An
LED bare chip emitting blue light is used to emit white light from
a light-emitting part. LED bare chips are bonded to the reflection
layer 5 with a silicon resin adhesive 31. A plurality of
light-emitting elements 3 is arranged in matrix, forming lines of
light-emitting elements.
An LED bare chip is an InGaN element, for example, in which a
light-emitting layer is formed on a translucent sapphire element.
The light-emitting layer is formed by sequentially laminating an
n-type nitride semiconductor layer, an InGan light-emitting layer,
and a p-type nitride semiconductor layer. An electrode to flow a
current to the light-emitting layer comprises a positive electrode
formed by an p-type electrode pad on the p-type nitride
semiconductor layer, and a negative electrode formed by an n-type
electrode pad on the n-type nitride semiconductor layer. These
electrodes are electrically connected by bonding wires 32. The
bonding wire 32 is made of a gold (Au) thin wire, and is connected
through a bump composed mainly of gold, to increase the mounting
strength and decrease damages of the LED bare chip.
Specifically, in each line of light-emitting elements 3, the
different polarity electrodes of two light-emitting elements 3
adjacent in the line extending direction, that is, the positive
electrode of one light-emitting element 3 and the negative
electrode of the other light-emitting element 3 are sequentially
connected by the bonding wire 32. As a result, a plurality of
light-emitting elements 3 forming each line of light-emitting
elements is electrically connected in series. Therefore, a
plurality of light-emitting elements 3 is simultaneously lit when
energized.
In each line of light-emitting elements, the electrode of the
light-emitting element 3 placed at the end of the line is connected
by the bonding wire 32 to the positive power feeding conductor 6 or
negative power feeding conductor 7. Therefore, a plurality of
light-emitting element lines is provided electrically in parallel,
and powered through the positive power feeding conductor 6 and
negative power feeding conductor 7.
The frame member 10 is bonded to the substrate 2 by applying
uncured silicone resin with a predetermined viscosity by means of a
dispenser, and then curing the resin by heating. The frame member
10 is shaped substantially rectangular, and has an inner surface
surrounding the reflection layer 5, positive power feeding
conductor 6, and negative power feeding conductor 7. The mounting
area of the light-emitting elements 3 is surrounded by the frame
member 10.
The sealing member 11 is made of translucent synthetic resin, for
example, transparent silicon resin, and is filled inside the frame
member 10, and provided on the substrate 2. The sealing member 11
seals the reflection layer 5, the portions of the positive power
feeding conductor 6 and negative power feeding conductor 7
connected to the bonding wires 32, the light-emitting elements 3,
and the bonding wires 32.
The sealing member 11 may contain appropriate quantity of
fluorescent material. A fluorescent material is excited by the
light emitted from the light-emitting elements 3, and emits light
with a different color from the light emitted from the
light-emitting elements 3. In the embodiment, as the light-emitting
element 3 emits blue light, a yellow fluorescent material emitting
yellow light that is a complementary color to blue light is used to
emit white light. The sealing member 11 is filled in the frame
member 10 in the uncured state by appropriate quantity, and then
cured by heating, and fixed to the substrate 2 and frame member 10.
Thus, the area sealed by the sealing member 11 is defined by the
frame member 10.
The anti-noise part 4 is connected to a pair of lead-out terminals
8. The anti-noise part 4 is a capacitor functioning as a bypass
element whose impedance is decreased for a noise. A ceramic chip
capacitor is used here. Specifically, a terminal electrode of a
ceramic chip capacitor is soldered to the edges of a pair of
lead-out terminals 8.
The lead-out terminals 8 are led out to the outside of the mounting
area for the light-emitting elements 3, specifically the outside of
the frame member 10. Therefore, the anti-noise part 4 does not
obstruct the light emitted from the light-emitting elements 3. The
lead-out terminals 8 are formed by leading out a part of the
positive power feeding conductor 6 and negative power feeding
conductor 7, and can be simplified in the structure.
As shown in FIG. 1, a power feeding connector 12 is soldered to the
substrate 2. The power feeding connector 12 is connected to the
power feeding terminals 9 of the positive power feeding conductor 6
and negative power feeding conductor 7, and is electrically
connected to a lighting control device described later. Through the
power feeding connector 12, power is supplied from the lighting
control device to the light-emitting elements 3, and the
light-emitting elements 3 are lit.
Next, the circuit configuration of the lighting apparatus 20 is
explained with reference to FIG. 4 and FIG. 5.
The lighting apparatus 20 comprises a lighting control device 21 as
a direct current power supply, and the light-emitting device 1. The
lighting control device 21 is connected to a commercial alternate
current power supply AC, and generates a direct current output from
the alternate current power supply AC. The commercial alternate
current power supply AC is connected to the input terminal of a
full-wave rectifier circuit 22. A smoothing capacitor 23 is
connected between the output terminals of the full-wave rectifier
circuit 22. It is allowed to use a power-factor improving circuit
constituting a booster chopper, instead of the smoothing capacitor
23. The smoothing capacitor 23 is connected to a direct current
voltage conversion circuit 24 and a current detection means 25. The
lighting control device 21 has a control function of feeding back a
current control signal to the direct current voltage conversion
circuit 24 according to a result of detection in the current
detection means 25, and making the output current constant.
The light-emitting device 1 is connected between the output
terminals of the lighting control device 21, through the power
feeding connector 12. The light-emitting device 3 comprises a
plurality of series circuits in which a plurality of light-emitting
elements 3 is connected in series, and a substrate 2 provided with
a capacitor C as an anti-noise part 4 connected in parallel to both
ends of the series circuit.
FIG. 5 is a schematic connection diagram showing a stray
capacitance in the lighting apparatus 20. As shown in the drawing,
the lighting apparatus 20 comprises a lighting control device 21
connected to a commercial alternate current power supply AC through
a power switch SW, and an apparatus main body 26 housing a
light-emitting device 1. The light-emitting device 1 is supplied a
direct current from the lighting control device 21, and a
light-emitting element 3 is lit. The apparatus main body 26 is made
of conductive metal such as aluminum, and maintained at a ground
potential.
When the light-emitting device 1 is energized, the light-emitting
elements 3 covered with the sealing member 11 are simultaneously
lit, and the light-emitting device is used as a surface light
source to emit white light. During emission of light, the
anti-noise part 4 placed outside the light-emitting element 3
mounting area does not obstruct the light emitted from the
light-emitting element 3, and prevents reduction in the optical
output. Further, while the light-emitting device 1 is lighting, the
light emitted from the light-emitting element 3 to the substrate 2
reflects on the front layer of the reflection layer 5 in the
direction of using the light.
As for a stray capacitance Cs, the apparatus main body 26
maintained at a ground potential forms one electrode, the positive
power feeding conductor 6, negative power feeding conductor 7, and
bonding wires 32 form the other electrode, and these electrodes are
electrostatically coupled through a dielectric substance. A stray
capacitance may be generated, when the positive power feeding
conductor 6, negative power feeding conductor 7, and bonding wires
32 connecting the light-emitting elements 3 are close to the
apparatus main body 26. In this case, even if the power switch SW
is being turned off, a minute current flows as a leak current when
a noise is superimposed on the power line, and the light-emitting
element 3 may be accidentally lit.
In the embodiment, a capacitor functioning as a bypass element is
connected as the anti-noise part 4 to both ends of the series
circuit connected to a plurality of light-emitting elements 3, and
a noise does not flow in the light-emitting elements 3, and is
bypassed by flowing in the capacitor. Therefore, even if a noise is
superimposed on the power line while the power switch SW is being
turned off, a minute current is prevented to flow as a leak current
in the light-emitting elements 3, and accidental lighting of the
light-emitting elements 3 can be prevented.
As described above, according to the embodiment, it is possible to
provide the light-emitting device 1 and lighting apparatus 20,
which are configured to prevent accidental lighting of the
light-emitting elements 3, and simply constructed so that the
anti-noise part 4 do not obstruct the light emitted from the
light-emitting elements 3.
Next, a second embodiment will be explained with reference to FIG.
6. The same components as those in the first embodiment are given
the same reference number, and an explanation thereof is
omitted.
FIG. 6 shows a bulb-type LED lamp 50 as a lighting apparatus. The
bulb LED lamp 50 basically comprises a light-emitting device 1
having the same structure as that of the first embodiment, and a
lighting control device 21. As a different point, an anti-noise
part 4 is a capacitor functioning as a protective element when a
high voltage caused by a noise such as static electricity is
applied to a light-emitting element 3. Therefore, the capacitor
prevents damages and breakage of the light-emitting element 3.
The bulb-type LED lamp 50 comprises a light-emitting device 1, a
main body 51 thermally connected to the light-emitting device 1, a
lighting control device 21 configured to control lighting of an
light-emitting element, a cover member 52 housing the lighting
control device 21, a base 53 fit to the cover member 52, and a
globe 54 placed over the light-emitting device 1 and fixed to the
main body 51.
The main body 51 is made of metallic material with high heat
conductivity such as aluminum, shaped substantially cylindrical
with the diameter gradually increasing from one end to the other,
and provided with a plurality of heat radiation fins on the cuter
circumferential surface. A fitting recess 51b to fit the cover
member 52 is formed at one end, of the main body 51, and a fixing
recess 51a for fixing the substrate 2 is formed at the other end of
the main body 51.
The lighting control device 21 comprises a flat rectangular
lighting circuit board and circuit components mounted on the
circuit board. The lighting circuit board is housed in the cover
member 52 with the longitudinal side erected. The substrate 2 and
lighting device 21 are electrically connected by a lead wire
passing through a not-shown wiring hole formed in the main body
51.
The cover member 52 is made of insulating material such as PBT
resin, and shaped substantially cylindrical along the fitting
recess 51b. A flange is formed on the entire outer circumference of
the middle of the cover member 52 and projects in the radial
direction from the cover member. The flange 52a serves as an
insulating part for insulating between the base 53 and one of the
main body 51.
The base 53 is E-shaped, and is electrically connected to the
lighting control device 21 by wiring. The base 53 comprises a
cylindrical shell with threads to be screwed into a lamp socket of
a not-shown lighting fixture, and an eyelet provided at the top of
the shell through an insulating part.
The globe 54 is made of light diffusing glass or synthetic resin,
and shaped spherical to be continued to the other end of the main
body 51. The globe 54 is formed to be gradually expanded from the
top of the sphere, and reduced from the maximum diameter
position.
In the bulb-type LED lamp 50 configured as above, for example, even
if an excess voltage caused by static electricity is applied to the
light-emitting element 3 during assembling, the light-emitting
element 3 is protected from damage and breakage by the anti-noise
part 4.
As shown in FIG. 4, in the light-emitting device 1, when an excess
voltage caused by static electricity is applied to the series
circuit connected to a plurality of light-emitting elements 3, the
electric charge caused by the static electricity is connected in
series with the electric charge of the capacitor C as an anti-noise
part 4. Therefore, the electric charge caused by the static
electricity is re-distributed to the capacitor C as an anti-noise
part 4, and the electric charge by the static electricity applied
to the series circuit of the light-emitting element 3 is reduced.
Therefore, the voltage applied to the light-emitting element 3 is
decreased, and the light-emitting element 3 is protected from
damage and breakage.
As described above, in the bulb-type LED lamp 50 according to the
second embodiment, it is possible to protect the light-emitting
element 3 from damage and breakage, and to prevent the anti-noise
part 4 from obstructing the light emitted from the light-emitting
element 3, with a simple structure.
Next, a third embodiment will be explained with reference to FIG. 7
and FIG. 8. The same components as those in the first embodiment
are given the same reference number, and an explanation thereof is
omitted. In the third embodiment, the configuration of the lead-out
terminal 8 is a main different point from the first embodiment.
As shown in FIG. 8, the lead-out terminal 8 of the positive power
feeding conductor 6 and negative power feeding conductor is
divided, and each lead-out terminal 8 is formed of a pair of
lead-out conductors 81, and two connection conductors 82. A pair of
lead-out conductors 81 is continued from the positive power feeding
conductor 6 and negative power feeding conductor 7, and the two
connection conductors 82 are independently formed with gap between
the edges of the power feeding conductors. Further, two connection
conductors 82 are spaced apart from each other by a predetermined
distance (insulation distance) L.
As shown in FIG. 7, a ceramic chip capacitor as an anti-noise part
4 is connected to the lead-out terminal 8. Specifically, three
ceramic capacitors 4a, 4b and 4c are sequentially placed from the
left to the right side in the drawing. The electrode terminal of
the left-side ceramic chip capacitor 4a is connected to the
lead-out conductor 81 led out from the positive power feeding
conductor 6 and the connection conductor 82. The terminal electrode
of the middle ceramic chip capacitor 4b is connected to the
connection conductor 82 and the next connection conductor 82. The
terminal electrode of the right-side ceramic chip capacitor 4c is
soldered to the lead-out conductor 81 led out from the negative
power feeding conductor 7.
The lead-out terminal 8 is provided with a predetermined distance
L. However, after the apparatus is used for a long time, a
migration phenomenon occurs, and the metallic component moves in
the distance L on the insulation layer on the surface of the
substrate 2 due to the influence of electric field, and the
insulation between the conductors is reduced.
However, in this embodiment, the lead-out terminal 8 is divided
into two or more portions, and three clearances, that is, the
insulation distance L is defined between a pair of lead-out
conductors 81, and the total distance is three times of one
insulation distance L. This increases the insulation distance
between the lead-out conductors, and prevents reduction of
insulation by the migration phenomenon.
It is proved by experiment that the insulation by the migration
phenomenon is defined by the total insulation distance L. In other
words, when the total insulation distance L is longer, the effect
to prevent insulation reduction by migration is higher.
An explanation will be given of an embodiment incorporating the
above-mentioned lead-out terminal 8 and anti-noise part 4.
Generally, when an electronic component is mounted, on a substrate,
the insulation distance (insulation distance) between the power
feeding conductors is determined by the size of an electronic
component. Thus, it is difficult to ensure the insulation distance
L enough to prevent reduction of the insulation by a migration
phenomenon.
For example, when one ceramic chip capacitor with capacitor of 0.3
.mu.F is used for the anti-noise part 4 (refer to FIGS. 1 and 2),
sufficient insulation distance L may not be ensured for the
lead-out terminals 8. In this case, to ensure the insulation
distance L, the capacitor is divided, and three 1 .mu.F capacitors
are connected in series, thereby the total capacity of 0.3 .mu.F
can be set, and the total insulation distance L can be set
longer.
Therefore, even though the insulation distance L is usually depend
on the size of the condenser, it is possible to prevent reduction
of the insulation due to a migration phenomenon, by setting the
total of the insulation distance L longer by dividing a capacitor
and connecting the divided capacitors.
A capacitor may be used in two or more pieces, and the number of
capacitors is not particularly limited. For example, two capacitors
may be used to ensure the distance (insulation distance) L. The
anti-noise part 4 may be configured to function as a bypass element
or a protective element.
As described above, in the light-emitting device 1 according to the
third embodiment, it is possible to prevent reduction of the
insulation by a migration phenomenon, and to prevent the anti-noise
part 4 from obstructing the light emitted from the light-emitting
element 3, with a simple structure.
Next, a fourth embodiment will be explained with reference to FIG.
9. FIG. 9 shows a circuit configuration of a lighting apparatus 20,
and corresponds to FIG. 4 in the first embodiment. The same
components as those in the first embodiment are given the same
reference number, and an explanation thereof is omitted.
A main different point of the fourth embodiment compared with the
first embodiment is that a constant-voltage diode ZD is connected
in anti-parallel at both ends of a plurality of series circuits in
which a plurality of light-emitting elements 3 as an anti-noise
part 4 is connected in series. The constant-voltage diode ZD as an
anti-noise part 4 functions as a protective element when a high
voltage caused by a noise such as static electricity is applied to
the light-emitting element 3.
For example, when static electricity flows into a series circuit in
which a plurality of light-emitting elements 3 is connected, if the
static electricity is forward to the constant-voltage diode ZD,
most current does not flow into the constant-voltage diode ZD, and
does not flow into the light-emitting elements 3. If the static
electricity is reverse to the constant-voltage diode ZD, the
constant-voltage diode Z is nonconductive up to a breakdown
voltage, but when a voltage is applied exceeding the breakdown
voltage, the diode ZD becomes conductive, and a current easily
flows from the light-emitting elements 3 to the constant-voltage
diode ZD.
As described above, in the lighting apparatus 20 according to the
fourth embodiment, a constant-voltage diode ZD is used as an
anti-noise part 4, it is possible to prevent a damage and breakage
of the light-emitting element 3, and to prevent the anti-noise part
4 from obstructing the light emitted from the light-emitting
element 3, with a simple structure, as in the second
embodiment.
Next, a fifth embodiment will be explained with reference to FIG.
10 to FIG. 14. The same components as those in the first embodiment
are given the same reference number, and an explanation thereof is
omitted.
FIG. 10 and FIG. 11 show a street light 20 installed for lighting a
street, as a lighting apparatus according to a fifth embodiment.
The street light 20 comprises a pole 102, and a lighting fixture
103 fixed to the pole. The pole 102 is stood on a roadside, and its
upper part is bent over a road. The lighting fixture 103 comprises
a main body, for example, a lamp body 104 connected to the pole 102
as shown in FIG. 11, a translucent cover 105 fit to the lamp body
104 covering the lower opening of the lamp body 104 facing to a
road, and at least one light source unit 106 housed in the lamp
body 104, opposing to the translucent cover 105. The lamp body 104
is formed of a metal, for example, formed by combining a plurality
of aluminum die-cast moldings. The translucent cover 105 is made of
reinforced glass.
The light-emitting device 1 arranged in the light source unit 106
will be explained. As shown in FIG. 12, FIG. 13 and FIG. 14, the
light-emitting device 1 comprises a substantially rectangular
substrate 2 with an insulative surface, a positive power feeding
conductor 6 and a negative power feeding conductor 7 formed as a
pattern on the surface of the substrate, alignment marks 35 and 36,
a first protective layer 37, a second protective layer 38, a
plurality of light-emitting elements 3, bonding wires, a frame
member 10, a sealing member 11, a power feeding connector 12, and
capacitors 4.
The substrate 2 is made of white ceramics, for example white
AL.sub.2O.sub.3 (aluminum oxide). The substrate 2 may be made of
aluminum oxide, and other ceramics mixed thereto. In this case, as
the aluminum oxide is a main component, and its content is
desirably higher than 70%.
An average reflectivity of the white substrate 2 against a visible
light area is higher than 80%, preferably over 85% and below 99%.
Therefore, the substrate 2 has a similar light reflectivity against
blue light with a specific emission wavelength of 440 to 460 nm
emitted from an LED described later, and yellow light with a
specific emission wavelength of 470 to 490 nm emitted from a
fluorescent material described later. One side of the substrate 2
is used as a component mounting surface 2a. The positive power
feeding conductor 6 and negative power feeding conductor 7
comprising a wiring pattern are arranged on the component mounting
surface 2a.
As shown in FIG. 12 and FIG. 13, the positive power feeding
conductor 6 comprises a base part 6a, and a common wire connector
6b. The common wire connector 6b extends straight. The base part 6a
and common wire connector 6b are substantially parallel, and are
connected as one body through an oblique pattern part. The base
part 6a is provided with a first positive electrode pad 6c and a
second positive electrode pad 6d as one body.
The negative power-feeding conductor 7 comprises a base part 7a, a
first wire connector 7b, an intermediate pattern part 7c, and a
second wire connector 7d. The negative power feeding conductor 7
surrounds the positive power feeding conductor 6.
In other words, the base part 7a is adjacent to the base part 6a of
the positive power feeding conductor with a predetermined
insulation distance L (refer to FIG. 13). The first negative
electrode pad 7e is arranged in the base part 7a of the negative
electrode side as one body. The first wire connector 7b is bent
approximately 90.degree. and continued to the base part 7a of the
negative electrode side. The first wire connector 7b is
substantially parallel to the common wire connector 6b of the
positive electrode side across a first element providing space
S1.
The intermediate pattern part 7c of the negative electrode side is
bent approximately 90.degree. and connected to the first wire
connector 7b. The intermediate portion in the longitudinal
direction of the intermediate pattern part 7c is adjacent to the
distal end of the common wire connector 6b with an insulation
distance B (refer to FIG. 13) more than the insulation distance L.
To ensure the insulation distance B, both ends of the intermediate
pattern part 7c are inclined in the reverse direction to each
other, and the intermediate pattern part 7c is substantially
curved. Therefore, the intermediate portion in the longitudinal
direction of the intermediate patter part 7c is separated away from
the distal end of the common wire connector 6b.
The second wire connector 7d is bent approximately 90.degree. and
continued to the intermediate pattern part 7c as one body.
Therefore, the second wire connector 7d is substantially parallel
to the common wire connector 6b of the positive electrode side
across a second element providing space S2. Therefore, the negative
power feeding conductor 7 surrounds the positive power feeding
conductor 6 from three directions.
A second negative electrode pad 7f is continued to the distal end
of the second wire connector 7d as one body, opposing the second
positive electrode pad 6d. The second negative electrode pad 7f is
apart from the second positive electrode pad 6d. Between these
pads, an intermediate pad 13 is arranged on the component mounting
surface 2a. The second negative electrode pad 7f, second positive
electrode pad 6d and intermediate pad 13 are led out to the outside
of the light-emitting element 3 mounting area described later,
forming the lead-out terminal 8. In this embodiment, the lead-out
terminal 8 is divided into two or more parts, and each part is
formed of a pair of lead-out conductor 81, and two connection
conductors 82. Each lead-out conductor 81 comprises a second
positive electrode pad 6d and second negative electrode pad 7f
(lead-out conductor) continued from the positive power feeding
conductor 6 and negative power feeding conductor 7, respectively,
and an intermediate pad (connection conductor) 13 placed between
the above pads with a clearance.
Further, on the component mounting surface 2a, there are provided
lighting check pads 28 and 29 for a lighting test, a temperature
check pad 34 for measuring temperatures, and a surface-mounted pad
33 for fixing components.
In other words, the lighting check pad 28 is connected to the
positive power feeding conductor 6, and the lighting check pad 29
is connected to the negative power feeding conductor 7. The
temperature check pad 34 is independently arranged near the
lighting check pad 29 and negative power feeding conductor 7,
without being electrically connected to them. The temperature of
the light-emitting device 1 can be measured by connecting a
thermocouple to the temperature check pad 34. The surface-mounted
pad 33 is formed in a pair, and arranged between the lighting check
pads 28 and 29.
The alignment marks 35 and 36 are provided on both sides of the
first wire connector 7b adjacent to the first element providing
space S1, and the second wire connector 7d adjacent to the second
element providing space S2, with the common wire connector 6b
placed between the spaces S1 and S2.
The positive power feeding conductor 6, negative power feeding
conductor 7, intermediate pad 13, lighting check pads 28 and 29,
surface-mounted pad 33, and alignment marks 35 and 36 are made of
the same metal such as silver, specifically made mainly of silver.
They are screen printed on the component mounting surface 22a. They
may be provided by plating instead of printing.
The first protective layer 37 and second protective layer 38 are
made of electrically insulating material, and printed on the
component mounting surface 2a by screen printing, covering mainly
the part of the silver printed element not sealed by the sealing
member 11 to prevent deterioration of this part.
Each of a plurality of light-emitting element 3 uses a
light-emitting element generating heat in the lighting state, for
example, a blue chip LED emitting blue light. These light-emitting,
elements 3 are preferably provided with a semiconductor
light-emitting layer on a sapphire glass translucent element board,
and a bare chip comprising a pair of element electrodes arranged on
the light-emitting layer.
The half of the light-emitting elements 3 is directly mounted on
the substrate 2 in the first element providing space S1. The
mounting is realized by bonding the element board to the component
mounting surface 2a by means of a transparent die-bond. The
light-emitting elements 3 mounted on the first element providing
space S1 are aligned in matrix. Similarly, the remaining
light-emitting elements 3 are directly mounted on the substrate 2
in the second element providing space S2. This mounting is also
realized by bonding the element board to the component mounting
surface 2a by means of a transparent die-bond. The light-emitting
elements 3 mounted on the second element providing space S2 are
aligned in matrix.
The lighting-emitting elements 3 disposed in the first element
providing space S1 and the light-emitting elements 3 disposed in
the second element providing space S2 are symmetrical with respect
to the common wire connector 6b.
The light-emitting elements 3 aligned in the direction in which the
common wire connector 6b of the positive power feeding conductor 6
and the first wire connector 7b of the negative power feeding
conductor 7 are arranged in parallel are connected in series by
bonding wires 47. The light-emitting element 3 placed at one end of
the series connected light-emitting element line 45R is connected
to the common wire connector 6b by a bonding wire 48. The
light-emitting element 3 placed at the other end of the
light-emitting element line 45R is connected to the first wire
connector 7b by a bonding wire 49.
Similarly, the light-emitting elements 3 are aligned in the
direction in which the common wire connector 6b and the second wire
connector 7d of the negative power feeding conductor 7 are arranged
in parallel, and connected in series by bonding wires 60. The
light-emitting element 3 placed at one end of the series connected
light-emitting element line 45L is connected to the common wire
connector 6b by a bonding wire 61. The light-emitting element 3
placed at the other end of the light-emitting element line 45L is
connected to the second wire connector 7d by a bonding wire 62. The
bonding wires 47 to 62 are made of thin metallic wire preferably a
gold wire, and are provided by wire bonding.
By electrically connecting the light-emitting elements 3 mounted on
the substrate 2 as described above, a chip-on-board (COB) type
light-emitting device 1 is formed. By the electrical connection,
the light-emitting elements 3 in the element providing spaces S1
and S2 are arranged as twelve lines of first light-emitting
elements 45R and twelve lines of second light-emitting elements
45L, electrically connected in parallel, each line consisting of
seven light-emitting elements 3, for example.
As shown in FIG. 12 and FIG. 14, the frame member 10 is shaped
rectangular, for example, and mounted on the component mounting
surface 22a, surrounding inside the wire connectors 6b, 7b and 7d,
the light-emitting element 3 mounting area, and the bonding wires
47 to 52. The frame member 10 is preferably made of white synthetic
resin. The frame member 10 is mounted on a part of the first
protective layer 37 and second protective layer 38. The second
positive electrode pad 6d, second negative electrode pad 7f, and
intermediate pad 13 forming the lead-out terminal 8 are arranged on
the substrate 2 outside the frame member 10.
The sealing member 11 is filled in the frame member 10, and
provided on the substrate, sealing the wire connectors 6b, 7b and
7d, the light-emitting elements 3, and the bonding wires 47 to 52,
in a buried state. The sealing member 57 uses translucent resin
material such as silicon resin. The sealing member may be made of
epoxy resin or urea resin, instead of silicon resin. The sealing
member 11 is gas permeable.
The sealing member 11 is mixed with fluorescent material (not
shown). Fluorescent material is excited by the light emitted from
the light-emitting elements 3, emits light of different color, and
forms light of color necessary for lighting by combining the
emitted different color of light and the emission color of the
light-emitting elements 3. Yellow fluorescent material is used to
obtain while illumination color under the condition using a blue
LED as a light-emitting element. Red, blue and yellow fluorescent
materials may be used to obtain white illumination color under the
condition using an ultraviolet-rays emitting LED as a semiconductor
light-emitting element.
White light is formed by mixing the blue light emitted from the
blue LED and yellow light complementary to the blue light. The
white light is emitted from the surface of the sealing member 11 to
the light using direction. Therefore, the surface or the
light-emitting surface of the sealing member 11 forms a
light-emitting surface 11a of the light-emitting device 1. The size
of the light-emitting surface 11a is defined by the frame member
10.
As shown in FIG. 12 and FIG. 14, on the component mounting surface
2a, one power feeding connector 12 comprising a surface mounting
component, and two capacitors 4 as anti-noise components are
mounted. The power feeding connector 12 is of a 2-pin type
comprising a first terminal pin 12a, and a second terminal pin 12b.
The power feeding connector 12 is soldered to the surface-mounted
pad 33, thereby being located between the lighting check pads 28
and 29. The first terminal pin 12a is soldered to the first
positive electrode pad 6c, and the second terminal pin 12b is
soldered to the first negative electrode pad 7e. A direct current
feeding insulation coating wire connected to a not-shown power
supply unit is inserted into the power feeding connector 12.
Thereby, power can be supplied to the light-emitting device 1
through the power feeding connector 12.
One of two capacitors 4 is soldered to one end of the second
positive electrode pad 6d and intermediate pad 13 of the positive
power feeding conductor 6, and is arranged across these parts. The
other capacitor 4 is soldered to the other end of the second
negative electrode pad 7f and intermediate pad 13 of the negative
power feeding conductor 7, and is arranged across these parts. Two
capacitors 4 are positioned outside the frame member 10, or outside
the light-emitting element 3 mounting area.
In the normal lighting state in which a direct current is supplied
to each light-emitting element 3, a current does not flow in the
capacitors 4. When a noise is superimposed on the power line and an
alternate current flows, a current flows in the capacitors 4, the
positive power feeding conductor 7 and negative power feeding
conductor 7 are shorted, thereby preventing supply of alternate
current to each light-emitting element 3.
As shown in FIG. 14, the height of the capacitors 4 is lower than
the power feeding connector 12. As the height of an electrical
component is higher, the component is placed away from the center
of the sealing member 11 excited to emit light, or the center of
emission. In FIG. 14, a reference J represents the distance between
the center of emission and the capacitor 4 lower than the power
feeding connector 12, K indicates the distance between the center
of emission and the power feeding connector 12 higher than the
capacitor 4, and K is larger than J.
By placing the electrical components according to their heights,
the angle .theta. formed between the component mounting surface 2a
and the emission line H emitted from the light-emitting element 3
indicated by an arrow in FIG. 14 can be reduced. Accordingly, it is
possible to increase the angle of the emitted light, while
preventing the emission line H from being interrupted by the high
power feeding connector 12.
As shown in FIG. 14, the light-emitting device 1 configured as
described above is supported by the device base 111 of the light
source unit 106 with the surface opposite to the component mounting
surface 2a closely contacting the bottom surface 112a of a mounting
section 112. In the state that the light-emitting device 1
supported as above is being secured to the lamp body 104, the
light-emitting surface 11a is opposed to the translucent cover
105.
For supporting the light-emitting device 1, a plurality of, for
example, two metallic holder plates 71 are screwed to the device
base 111. The end portions of the holder plates 71 are opposed to
the circumference of the substrate 2, and are provided with
metallic springs 72 to press the circumference of the substrate 2.
The springs 72 holds the rear side of the substrate 2 closely
contacting the bottom surface 112a.
As described above, in the light-emitting device 1 and street light
according to the fifth embodiment, it is possible to prevent
reduction of the insulation by a migration phenomenon, and to
prevent the anti-noise part 4 from obstructing the light emitted
from the light-emitting element 3, with a simple structure.
While certain embodiments have been described, these embodiments
have been presented by way of example only, and are not intended to
limit the scope of the invention. Indeed, the novel embodiments
described herein may be embodied in a variety of other forms;
furthermore, various omissions, substitutions and changes in the
form of the embodiments described herein may be made without
departing from the spirit of the invention. The accompanying claims
and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
invention.
For example, a capacitor and a constant-voltage diode are used as
anti-noise parts. Anti-noise parts are not particularly limited to
these parts. A plurality of light-emitting devices may be connected
in series or parallel to increase the light quantity of a lighting
apparatus. A lighting apparatus is applicable to a lighting fixture
used indoors and outdoors, and a display unit.
As a method of mounting light-emitting elements on a substrate, a
chip-on-board method to directly insert a bare chip into a
substrate, and a soldering method of soldering packaged
surface-mounted components are applicable. A mounting method is not
particularly limited.
* * * * *